Deflectable medical devices

ABSTRACT

A deflective medical device including a catheter shaft having a distal end, and an ablation electrode disposed at the distal end of the catheter shaft. A deflection body is provided within the catheter shaft, and the deflection body includes a longitudinally extending spine. Multiple slots are formed in the deflection body, and the slots define a group of ribs. A flex member is disposed distal to the deflection body, and an intermediate region is defined between the deflection body and the flex member. A deflection mechanism is coupled to the intermediate region, which includes a retaining member, a collar, and a pull wire coupled to the collar.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119 to U.S.Provisional Application Ser. No. 61/780,876, filed Mar. 13, 2013, theentirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present disclosure pertains to medical devices, and methods formanufacturing medical devices. More particularly, the present disclosurepertains to deflectable medical devices and methods for manufacturingand using such devices.

BACKGROUND

A wide variety of intracorporeal medical devices have been developed formedical use, for example, intravascular use. Some of these devicesinclude guidewires, catheters, and the like. These devices aremanufactured by any one of a variety of different manufacturing methodsand may be used according to any one of a variety of methods. Of theknown medical devices and methods, each has certain advantages anddisadvantages. There is an ongoing need to provide alternative medicaldevices as well as alternative methods for manufacturing and usingmedical devices.

BRIEF SUMMARY

The present disclosure provides a deflective medical device forperforming nerve ablation of a blood vessel within a patient's body. Thedistal portion of the device is easily deflective, and maintains asubstantial area of contact with the inner surface of the blood vesselwhen ablation is performed.

According to a first aspect, a deflective medical device includes acatheter shaft having a distal end. An ablation electrode is disposed atthe distal end of the catheter shaft. The device also includes adeflection body having a spine that extends longitudinally along thedeflection body. Multiple slots are formed in the deflection body, andthose slots define a group of ribs. A flex member is disposed distal tothe deflection body, and an intermediate region is defined between theflex member and the deflection body. A deflection member is coupled tothe intermediate region, and includes a retaining member, a collar and apull wire coupled to the collar. The retaining member is disposed toslide within the collar, and it secures the pull wire to theintermediate region. Further, the retaining member also limits axialmovement of the pull wire relative to the catheter shaft.

According to another aspect, the present disclosure provides adeflective medical device including a catheter shaft having a distalend. An ablation electrode is disposed at the distal end of the cathetershaft. The medical device further includes a deflection body having alongitudinally extending spine. Multiple slots are formed in thedeflection body to define a group of ribs. A flex member is disposeddistal to the deflection body. An intermediate region is defined betweenthe deflection body and the flex member. The intermediate region has anopening extending from an outer surface to an inner surface thereof. Adeflection mechanism is coupled to the intermediate region of thecatheter shaft. The deflection mechanism includes a retaining portionand a pull wire portion. The retaining portion includes a collarextending at least partially around the outer surface of theintermediate region. The pull wire portion passes through the openingwithin the intermediate region, and extends proximally along a lumen ofthe deflection body.

The above summary of the exemplary embodiments does not describe all thefeatures of those embodiments, or every implementation of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of various embodiments in connectionwith the accompanying drawings, in which:

FIG. 1 is a schematic view of a renal nerve modulation system coupled toa patient's body, for performing ablation, in accordance with thepresent disclosure;

FIG. 2 is a partially cut away side view of a portion of an examplecatheter;

FIG. 3 is a partial cross-sectional side view of an example catheterdisposed within a body lumen;

FIG. 3A is a partial cross-sectional side view of another examplecatheter disposed within a body lumen;

FIG. 4 is a cross-sectional view of an illustrative deflectable medicaldevice incorporating an illustrative deflection mechanism;

FIG. 5 is a cross-sectional view of another illustrative deflectablemedical device incorporating an illustrative deflection mechanism;

FIG. 6 is a cross-sectional view of another illustrative deflectablemedical device incorporating an illustrative deflection mechanism;

FIG. 7 is a cross-sectional view of another illustrative deflectablemedical device incorporating an illustrative deflection mechanism;

FIGS. 8A-8B are side views of another illustrative deflectable medicaldevice incorporating an illustrative deflection mechanism;

FIG. 9 is a side view of another illustrative deflection mechanism;

FIGS. 10A-10C are side views of another illustrative deflectable medicaldevice incorporating an illustrative deflection mechanism;

FIGS. 11A-11C are side views of another illustrative deflectable medicaldevice incorporating an illustrative deflection mechanism; and

FIG. 12 is a side view of another illustrative deflection mechanism.

While the invention is amenable to various modifications and alternativeforms, specifics thereof depict example in the drawings described indetail. However, the intention is not to limit aspects of the inventionto the particular embodiments described herein. On the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition can be construed through the claims, or isexplicitly provided elsewhere in this specification.

All numeric values are herein assumed to be modified by the term“about,” whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the term “about” may be indicative ofnumbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range, including the extreme points of the range.

Although some suitable dimensions, ranges and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofskill in the art, incited by the present disclosure, would understanddesired dimensions, ranges and/or values may deviate from thoseexpressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

For purposes of this disclosure, “proximal” refers to the directioncloser to the operator of the device, and“distal” refers to thedirection opposite to “proximal, i.e., farther from the operator of thedevice.

The following detailed description should be read with reference to thedrawings. Wherever possible, elements/components having the samestructure and/or functionality have been represented by same numerals.The detailed description and the drawings, which are not necessarily toscale, depict illustrative embodiments and are not intended to limit thescope of the disclosure. The illustrative embodiments depicted areintended only as exemplary. Selected features of any illustrativeembodiment may be incorporated into an additional embodiment unlessclearly stated to the contrary.

It is noted that references in the specification to “an embodiment”,“some embodiments”, “other embodiments”, etc., indicate that theembodiment described may include a particular feature, structure, orcharacteristic, but every embodiment may not necessarily include theparticular feature, structure, or characteristic. Moreover, such phrasesare not necessarily referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with one embodiment, it should be understood that suchfeature, structure, or characteristic may also be used in connectionwith other embodiments whether or not explicitly described unlesscleared stated to the contrary.

Certain treatments may require the temporary or permanent interruptionor modification of select nerve function. One example treatment is renalnerve ablation which is sometimes used to treat conditions related tohypertension and/or congestive heart failure. The kidneys produce asympathetic response to congestive heart failure, which, among othereffects, increases the undesired retention of water and/or sodium.Ablating some of the nerves running to the kidneys may reduce oreliminate this sympathetic function, which may provide a correspondingreduction in the associated undesired symptoms.

Many nerves (and nervous tissue such as brain tissue), including renalnerves, run along the walls of or in close proximity to blood vesselsand thus can be accessed intravascularly through the walls of the bloodvessels. In some instances, it may be desirable to ablate perivascularnerves using a radio frequency (RF) electrode. In other instances, theperivascular nerves may be ablated by other means including applicationof thermal, ultrasonic, laser, microwave, and other related energysources to the vessel wall.

Because the nerves are hard to visualize, treatment methods employingsuch energy sources have tended to apply the energy as a generallycircumferential ring to ensure that the nerves are modulated. However,such a treatment may result in thermal injury to the vessel wall nearthe electrode and other undesirable side effects such as, but notlimited to, blood damage, clotting, weakened vessel wall, and/or proteinfouling of the electrode.

While the devices and methods described herein are discussed relative torenal nerve modulation through a blood vessel wall, it is contemplatedthat the devices and methods may be used in other applications wherenerve modulation and/or ablation are desired. The term modulation refersto ablation and other techniques that may alter the function of affectednerves.

FIG. 1 is a schematic view of an example renal nerve modulation system10 in situ. System 10 may include a renal ablation catheter 12 and oneor more conductive element(s) 14 for providing power to catheter 12. Aproximal end of conductive element(s) 14 may be connected to a controland power element 16, which supplies necessary electrical energy toactivate one or more electrodes (e.g., electrode 24 as shown in FIG. 3)disposed at or near a distal end of catheter 12. When suitablyactivated, the electrodes are capable of ablating adjacent tissue. Theterms electrode and electrodes may be considered to be equivalent toelements capable of ablating adjacent tissue in the disclosure whichfollows. In some instances, return electrode patches 18 may be suppliedon the legs or at another conventional location on the patient's body tocomplete the circuit.

Control and power element 16 may include monitoring elements to monitorparameters such as power, temperature, voltage, amperage, impedance,pulse size and/or shape and other suitable parameters, with sensorsmounted along catheter, as well as suitable controls for performing thedesired procedure. In some embodiments, power element 16 may control aradio frequency (RF) electrode. The electrode may be configured tooperate at a frequency of approximately 460 kHz. It is contemplated thatany desired frequency in the RF range may be used, for example, from400-500 kHz. It is further contemplated that additionally and/or otherablation devices may be used as desired, for example, but not limited toresistance heating, ultrasound, microwave, and laser devices and thesedevices may require that power be supplied by the power element 16 in adifferent form.

FIG. 2 is a partially cut away side view of catheter 12. Here, some ofthe structural features of catheter 12 can be seen. For example,catheter 12 may include a catheter shaft 20. Catheter shaft 20 may takethe form of a metallic and/or polymer shaft and may includevisualization (e.g., marker bands) and/or reinforcing structures (e.g.,braids, coils, etc.) commonly used for catheter shafts. In at least someembodiments, catheter shaft 20 may form or define an outer surface ofcatheter 12. An ablation member or electrode 24 may be attached tocatheter shaft 20. Ablation member 24 may be formed at or otherwise forma distal tip of catheter shaft 20. In general, ablation member 24 may beconfigured to ablate target tissue at or near a body lumen. For example,ablation member 24 may be used to ablate a renal nerve adjacent to arenal artery. Ablation member 24 may vary and may include a number ofstructures such as a plurality of wires (e.g., two wires) that connectwith electrode wire 14 and, ultimately, control and power element 16.Electrode wire 14 may be soldered to a side slot (not explicitly shown)on the ablation member 24, for example.

Ablation member 24 may also include other structures and/or featuresassociated typically associated with ablation (e.g., thermal ablation)such as a temperature monitoring member (not explicitly shown), whichmay take the form of a thermocouple or thermistor. In at least someembodiments, a thermistor including two thermistor wires may be disposedadjacent to ablation member 24. In some embodiments, the wires are notphysically connected to ablation member 24. The thermistor wires mayterminate in the center bore of the ablation member 24 and may be pottedwith a thermally conducting epoxy in a plastic tube which is then gluedto the bore of the ablation member 24.

When conducting a medical procedure that involves ablation, it may bedesirable to place the ablation member (e.g., ablation member 24) nearthe target tissue so as to ablate the target while minimizing damage tonon-targeted tissue. In order to more specifically place or steercatheter 12 to a position adjacent to the intended target, catheter 12may be configured to be deflectable. Accordingly, catheter 12 mayinclude a tubular member 26 that includes a flex body 28 that can beselectively bent. This allows a user to orient, for example, ablationmember 24 in a desirable position within a body lumen. To effectdeflection, one or more pull wires or actuation members may be coupledto flex body 28. This allows a user to actuate (e.g., “pull”) one orboth of wires to deflect flex body 28 and, thus, catheter 12 (e.g.,ablation member 24). In addition, wires may be stiff enough so that theycan also be used to provide a pushing force on flex body 28 to, forexample, straighten flex body 28. In some instances, the actuationmember may take the form of a continuous wire that is looped through orotherwise coupled to a distal end of flex body 28 so as to define a pairof wire section). In other instances, the actuation member may includeone or more individual wires that are attached, for example, to thedistal end of flex body 28.

To further aid in properly orienting catheter 12 within a body lumen, aflex tube 32 may be coupled to flex body 28 (e.g., at a distal end offlex body 28). Flex tube 32 may have a plurality of slots 34 formedtherein. In general, flex tube 32 is configured to be flexible so thatthe distal portion of catheter 12 (e.g., adjacent to ablation member 24)can bend upon encountering the wall of a body lumen. Accordingly, flextube 32 can bend when/if ablation member 24 engages the wall of the bodylumen during deflection of flex body 28 so that ablation member 24 mayatraumatically follow along the wall of the body lumen.

In at least some embodiments, flex body 28 and flex tube 32 are twodistinct structures that are attached to one another. In otherembodiments, flex body 28 and flex tube 32 are formed in tubular member26 by selectively cutting the desired pattern into tubular member 26.For example, tubular member 26 may be cut in a first pattern thatdefines flex body 28 and tubular member 26 may be cut in a secondpattern that defines flex tube 32. The cut patterns may be substantiallycontinuous (e.g., where relatively little or no appreciable spacing isdefined between the patterns) or the patterns may be longitudinallyspaced so that a gap is defined therebetween. Analogously, flex body 28and flex tube 32 may be substantially continuous with one another orlongitudinally spaced from one another so that an intermediate region 22is defined therebetween. In some embodiments flex body 28 and flex tube32 may be formed from a nickel-titanium alloy, such as, but not limitedto, nitinol, although this is not required. It is contemplated that flexbody 28 and flex tube 32 may be formed from any material desired.

Catheter 12 may also include a number of additional features commonlyassociated with medical devices. For example, catheter 12 may includeradiopaque markers or bands, additional or alternative catheter shaftconstructions (e.g., having lumens, reinforcements, balloons, or othercatheter structures), a proximal hub and strain relief, and the like.

FIG. 3 illustrates catheter 12 disposed in a blood vessel 40. Here itcan be seen how flex body 28 (and flex tube 32) can aid in theorientation of catheter 12 within blood vessel 40. In this example, apull wire may be actuated to cause flex body 28 to bend. This bendsablation member 24 toward the wall of blood vessel 40. Flex tube 32allows catheter 12 to further bend so that ablation member 24 can tracealong and lay flat against the wall of blood vessel 40. However, otherembodiments are also contemplated that allow the tip of the electrode 24to touch the wall of blood vessel 40 rather than lay flat against thewall. For example, FIG. 3A illustrates catheter 12 that may be similarin form and function to other catheters disclosed herein. Catheter 12may lack flex tube 32. This allows the tip of electrode 22 to contactthe wall of blood vessel 40. In some embodiments, the tip of electrode22 may be insulated but thermally conductive and energy may be emittedfrom a point proximal of the tip. This may allow the ablation point ofthe electrode to be spaced from or otherwise positioned away from thevessel wall and may also improve heat dissipation at the point ofelectrode 22 contact, which may reduce potential thermal damage to theinterior vessel wall.

In some instances, it may be desirable to use a stainless steel pullwire to affect deflection of the distal end region of catheter 12.However, it may be challenging to attach a stainless steel pull wire toa nitinol tubular member 26. The force necessary to deflect a nitinoltube may require an attachment means that will securely connect a pullwire to the tube 26. However, typical techniques, such as, but notlimited to, welding, soldering, or adhesive bonding may not be suitablefor use with nitinol.

FIG. 4 illustrates a cross-section of a section of tubular member 26having a pull wire 36 affixed thereto. For simplicity, catheter shaft 12is not shown, although it should be understood tubular member 26 may beused in conjunction with catheter shaft 12. In some embodiments, pullwire 36 may be formed from stainless steel, although this is notrequired. It is contemplated that pull wire 36 may be formed from anymaterial desired. In some instances, pull wire 36 may be welded orotherwise attached to a tubular member or collar 38. While collar 38 isdescribed as tubular, collar 38 may take any shape desired. Collar 38may define a lumen 40 for receiving a retaining member 42 therethrough.In some embodiments, collar 38 may have an inner diameter that issubstantially the same size as an outer diameter of retaining member 42or slightly larger than the outer diameter of retaining member 42.Collar 38 may either partially or completely surround retaining member42. Together, collar 38, pull wire 36, and retaining member 42 may froma deflection mechanism.

Retaining member 42 may be a retaining pin having a generally circularcross-section and tapered end portions, to facilitate insertion of pin42 through apertures or holes 44 a, 44 b provided within intermediateregion 22. In some embodiments, these holes 44 a, 44 b may be provideddiametrically opposite one another, although this is not required. Thediameter, or cross-section, of holes 44 a, 44 b may be sized to receiveretaining member 42. Retaining member 42 may be a retaining pin having acircular cross-section and tapered end portions, to facilitate ease ofinsertion of the pin through either of the holes 44 a, 44 b. It iscontemplated that retaining member 42 may be sized such that retainingmember 42 is press fit or friction fit within apertures 44 a, 44 b. Insome embodiments, retaining member 42 may have a length greater than aninner diameter of tubular member 26 such that retaining member 42 issecured within both apertures 44 a, 44 b.

Pull wire 36 may have a first portion 46 extending generally parallel toa longitudinal axis of tubular member 26 and a second portion 48extending generally orthogonal to the longitudinal axis of tubularmember 26, providing an L-shaped structure to a distal end region ofpull wire 36. As shown, the outer surface of the second portion 48 maybe attached to the outer portion of collar 38. Pull wire 36 may bewelded or otherwise fixedly secure to collar 38. Further, pull wire 36may be attached to collar 38 such that the first portion 46 of pull wire36 is positioned at an offset from the center of tubular member 26. Thismay allow for an effective transfer of any deflective force applied tothe pull wire 36, towards the distal portion of the catheter shaft 12.

To assemble pull wire 36 with tubular member 26, the collar 38 may firstbe attached to the pull wire 36 external to tubular member 26. Pull wire36 and collar 38 may then be inserted into a lumen of the tubular member26. On insertion, lumen 40 of collar 38 may be vertically aligned withthe holes 44 a, 44 b. Thereafter, retaining pin 42 may be first insertedthrough either of holes 44 a, 44 b, then through lumen 40 and finallythrough the opposite hole 44 a, 44 b. Positioned in this manner,retaining pin 42 orients itself substantially orthogonal to thelongitudinal axis tubular member 26. The proximal end of pull wire 36may extend proximally to an appropriate control mechanism (not shown),which may be a handle configured to operate the pull wire 36.

When pull wire 36 is operated through the control mechanism (when soprovided), the distal portion of the catheter shaft 12 can be easilydeflected in an intended manner. For example, pull wire 36 can bepositioned in a particular configuration (e.g. along the longitudinalaxis or offset from the longitudinal axis) to achieve a desireddeflection of the distal portion of the catheter shaft 12. Also, sincethe end portions of the retaining pin 42 are secured within holes 44 a,44 b, the pin 42 may be substantially restricted from axial movementand/or shifting/moving along the longitudinal axis of tubular member 26.

FIG. 5 illustrates a cross-section of a section of another illustrativetubular member 126 having a pull wire 136 affixed thereto. Tubularmember 126 may be similar in form and function to tubular member 26discussed above. In some instances, tubular member 126 may include aflex body 128, flex tube 132, and intermediate region 122 that may besimilar in form and function to flex body 28, flex tube 32, andintermediate region 22 discussed above, While not explicitly shown,tubular member 126 may be used in conjunction with a catheter, such ascatheter 12. In some embodiments, pull wire 136 may be formed fromstainless steel, although this is not required. It is contemplated thatpull wire 136 may be formed from any material desired. In someinstances, pull wire 136 may be secured within a lumen 138 extendingthrough retaining member or pin 142. It is contemplated that in someinstances, pull wire 136 may be welded directly to retaining member 142.In other instances, a ball weld may be placed onto the end of pull wire136 or a mechanical crimp can be added to the distal end of pull wire136 to prevent the pull wire 136 from exiting lumen 138. However, anysuitable means for attaching pull wire 136 to retaining member 142 maybe used. While pull wire 136 is illustrated as extending completelythrough retaining member 142, it is contemplated that pull wire 136 mayextend only partially through lumen 138. Together, pull wire 136 andretaining member 142 may from a deflection mechanism.

Retaining member 142 may be a retaining pin having a generally circularcross-section and tapered end portions, to facilitate insertion of pin142 through apertures or holes 144 a, 144 b provided within intermediateregion 122. In some embodiments, these holes 144 a, 144 b may beprovided diametrically opposite one another, although this is notrequired. The diameter, or cross-section, of holes 144 a, 144 b may besized to receive retaining member 142. Retaining member 142 may be aretaining pin having a circular cross-section and tapered end portions,to facilitate ease of insertion of the pin through either of the holes144 a, 144 b. In some embodiments, retaining member 142 may have alarger diameter main body 148 and small end regions 150 a, 150 b. Thetapered shape of retaining member 142 may allow retaining member 142 tobe self-centering. It is contemplated that end regions 150 a, 150 b maybe sized such that retaining member 142 is press fit or friction fitwithin apertures 144 a, 144 b. In some embodiments, retaining member 142may have a length greater than an inner diameter of tubular member 126such that retaining member 142 is secured within both apertures 144 a,144 b. Further, while lumen 138 is illustrated as offset from a centerlongitudinal axis of tubular member 126, this is not required. Lumen 138may be formed in any portion of retaining member 142 desired to achievethe desired deflection.

To assemble pull wire 136 and retaining member 142 with tubular member126, the shape memory characteristics of nitinol may be utilized. Thenitinol tubular member 126 may be chilled to an appropriate temperature(for example, below the transformation temperature) and then placed in afixture that orients tubular member 126 into an oval or ellipticalshape. Orienting tubular member 126 into an oval shape at reducedtemperature allows the nitinol material to be deformed without damage,yet allow it to return to its normal (generally circular) shape whenreturned to room temperature. While in the elliptical shape, the majoraxis may be sufficiently large to allow the pull wire 136/retainingmember 142 assembly to pass through the inner diameter of tube 126. Oncethe ends 150 a, 150 b of retaining member 142 are aligned with holes 144a, 144 b, tubular member 126 may be removed from the ovalizing fixtureand/or allowed to warm to room temperature. As tubular member 126resumes its normal, generally circular, shape, the end regions 150 a,150 b of retaining member 142 engage holes 144 a, 144 b. The pull wire136/retaining member 142 assembly may then be fixedly secured to tubularmember 126 and pull wire 136 can be actuated to achieve deflection oftubular member 126.

When pull wire 136 is operated through the control mechanism (when soprovided), the distal portion of the catheter shaft can be easilydeflected in an intended manner. For example, pull wire 136 can bepositioned in a particular configuration (e.g. along the longitudinalaxis or offset from the longitudinal axis) to achieve a desireddeflection of the distal portion of the catheter shaft. Also, since theend portions of the retaining pin 142 are secured within holes 144 a,144 b, the pin 142 may be substantially restricted from axial movementand/or shifting/moving along the longitudinal axis of tubular member126.

FIG. 6 illustrates a cross-section of a section of another illustrativetubular member 226 having a pull wire 236 affixed thereto. Tubularmember 226 may be similar in form and function to tubular member 26discussed above. In some instances, tubular member 226 may include aflex body 228, flex tube 232, and intermediate region 222 that may besimilar in form and function to flex body 28, flex tube 32, andintermediate region 22 discussed above, While not explicitly shown,tubular member 226 may be used in conjunction with a catheter, such ascatheter 12. In some embodiments, pull wire 236 may be formed fromstainless steel, although this is not required. It is contemplated thatpull wire 236 may be formed from any material desired. In someinstances, pull wire 236 may be attached to a housing 248. In someembodiments, housing 248 may be formed from stainless steel, althoughthis is not required. Housing 248 may have a generally trapezoidalshape. However, it is contemplated that housing 248 may take any shapedesired. Housing 248 may include a first through hole 250 extendinggenerally parallel to the longitudinal axis of tubular member 226 and asecond through hole 240 extending generally orthogonal to the firstthrough hole 250. It is contemplated that first through hole 250 may notextend completely through housing 248. Pull wire 236 may be welded orotherwise fixedly secured within first through hole 250. The firstthrough hole 250 may be positioned at an offset from the centrallongitudinal axis of tubular member 226, although this is not required.This may allow for an effective transfer of any deflective force appliedto the pull wire 236, towards the distal portion of the catheter shaft.In some embodiments, second through hole 240 may have an inner diameterthat is substantially the same size as an outer diameter of retainingmember 242 or slightly larger than the outer diameter of retainingmember 242. Together, housing 248, pull wire 236, and retaining member242 may from a deflection mechanism.

Retaining member 242 may be a retaining pin having a generally circularcross-section and tapered end portions, to facilitate insertion of pin242 through apertures or holes 244 a, 244 b provided within intermediateregion 222. In some embodiments, these holes 244 a, 244 b may beprovided diametrically opposite one another, although this is notrequired. The diameter, or cross-section, of holes 244 a, 244 b may besized to receive retaining member 242. Retaining member 242 may be aretaining pin having a circular cross-section and tapered end portions,to facilitate ease of insertion of the pin through either of the holes244 a, 244 b. It is contemplated that retaining member 242 may be sizedsuch that retaining member 242 is press fit or friction fit withinapertures 44 a, 44 b. In some embodiments, retaining member 242 may havea length greater than an inner diameter of tubular member 226 such thatretaining member 242 is secured within both apertures 244 a, 244 b.

To assemble pull wire 236 with tubular member 226, the housing 248 andpull wire 236 may first be attached external to tubular member 226. Pullwire 236 and housing 248 may then be inserted into a lumen of thetubular member 226. On insertion, through hole 240 of housing 248 may bevertically aligned with the holes 244 a, 244 b. Thereafter, retainingpin 242 may be first inserted through either of holes 244 a, 244 b, thenthrough hole 240 and finally through the opposite hole 244 a, 244 b.Positioned in this manner, retaining pin 242 orients itselfsubstantially orthogonal to the longitudinal axis tubular member 226.The proximal end of pull wire 236 may extend proximally to anappropriate control mechanism (not shown), which may be a handleconfigured to operate the pull wire 236.

When pull wire 236 is operated through the control mechanism (when soprovided), the distal portion of the catheter shaft can be easilydeflected in an intended manner. For example, pull wire 236 can bepositioned in a particular configuration (e.g. along the longitudinalaxis or offset from the longitudinal axis) to achieve a desireddeflection of the distal portion of the catheter shaft. Also, since theend portions of the retaining pin 242 are secured within holes 244 a,244 b, the pin 242 may be substantially restricted from axial movementand/or shifting/moving along the longitudinal axis of tubular member226.

FIG. 7 illustrates a cross-section of a section of another illustrativetubular member 326 having a pull wire 336 affixed thereto. Tubularmember 326 may be similar in form and function to tubular member 26discussed above. In some instances, tubular member 326 may include aflex body 328, flex tube 332, and intermediate region 322 that may besimilar in form and function to flex body 28, flex tube 32, andintermediate region 22 discussed above, While not explicitly shown,tubular member 326 may be used in conjunction with a catheter, such ascatheter 12. In some embodiments, pull wire 336 may be formed fromstainless steel, although this is not required. It is contemplated thatpull wire 336 may be formed from any material desired. In someinstances, pull wire 336 may be secured directly to a retaining memberor pin 342. It is contemplated that in some instances, pull wire 336 maybe welded or otherwise attached to retaining member 342. Together, pullwire 336 and retaining member 342 may from a deflection mechanism.

Pull wire 336 may have a first portion 346 extending generally parallelto a longitudinal axis of tubular member 326 and a second portion 348extending generally orthogonal to the longitudinal axis of tubularmember 326, providing an L-shaped structure to a distal end region ofpull wire 336. As shown, the outer surface of the second portion 348 maybe attached to the retaining member 342. Pull wire 336 may be attachedto retaining member 342 such that the first portion 346 of pull wire 336is positioned at an offset from the center of tubular member 326. Thismay allow for an effective transfer of any deflective force applied tothe pull wire 336, towards the distal portion of the catheter shaft.

Retaining member 342 may be a retaining pin having a generally circularcross-section and tapered end portions, to facilitate insertion of pin342 through apertures or through holes 344 a, 344 b provided withinintermediate region 322. In some embodiments, these holes 344 a, 344 bmay be provided diametrically opposite one another, although this is notrequired. The diameter, or cross-section, of holes 344 a, 344 b may besized to receive retaining member 342. Retaining member 342 may be aretaining pin having a circular cross-section and tapered end portions,to facilitate ease of insertion of the pin through either of the holes344 a, 344 b. It is contemplated that retaining member 342 may be sizedsuch that retaining member 342 is press fit or friction fit withinapertures 344 a, 344 b. In some embodiments, retaining member 342 mayhave a length greater than an inner diameter of tubular member 326 suchthat retaining member 342 is secured within both apertures 344 a, 344 b.

To assemble pull wire 336 and retaining member 342 with tubular member326, the shape memory characteristics of nitinol may be utilized. Thenitinol tubular member 326 may be chilled to an appropriate temperatureand then placed in a fixture that orients tubular member 326 into anoval or elliptical shape. Orienting tubular member 326 into an ovalshape at reduced temperature allows the nitinol material to be deformedwithout damage, yet allow it to return to its normal (generallycircular) shape when returned to room temperature. While in theelliptical shape, the major axis may be sufficiently large to allow thepull wire 336/retaining member 342 assembly to pass through the innerdiameter of tube 326. Once the retaining member 342 is aligned withholes 344 a, 344 b, tubular member 326 may be removed from the ovalizingfixture and/or allowed to warm to room temperature. As tubular member326 resumes its normal, generally circular, shape, retaining member 342engages holes 344 a, 344 b. The pull wire 336/retaining member 342assembly may then be fixedly secured to tubular member 326 and pull wire336 can be actuated to achieve deflection of tubular member 326.

When pull wire 336 is operated through the control mechanism (when soprovided), the distal portion of the catheter shaft can be easilydeflected in an intended manner. For example, pull wire 336 can bepositioned in a particular configuration (e.g. along the longitudinalaxis or offset from the longitudinal axis) to achieve a desireddeflection of the distal portion of the catheter shaft. Also, since theend portions of the retaining pin 342 are secured within holes 344 a,344 b, the pin 342 may be substantially restricted from axial movementand/or shifting/moving along the longitudinal axis of tubular member326.

FIG. 8A illustrates a side view of another illustrative tubular member426 and deflection mechanism 436. Tubular member 426 may be similar inform and function to tubular member 26 discussed above. In someinstances, tubular member 426 may include a flex body 428, flex tube432, and intermediate region 422 that may be similar in form andfunction to flex body 28, flex tube 32, and intermediate region 22discussed above, While not explicitly shown, tubular member 426 may beused in conjunction with a catheter, such as catheter 12.

The deflection mechanism 436, for facilitating deflection of the tubularmember 426 and/or catheter, may include a retaining portion 440 and apull wire portion 438. The retaining portion 440 may be a generally ringshape collar, which is configured to be disposed over an outer surfaceof tubular member 426. The inner diameter of the retaining portion 440may be substantially the same size as or slightly larger than the outerdiameter of the intermediate region 422. In some embodiments, retainingportion 440 may extend all the way around the outer perimeter of tubularmember 426 while in other embodiments, retaining portion 440 may extendonly partially around the outer perimeter of tubular member 426.

In some instances, retaining portion 440 and pull wire portion 438 maybe formed as a unitary structure, as shown in FIG. 8A. In otherinstances, retaining portion 440 and pull wire portion 438′ may beformed as separate structures and subsequently secured to one another,as shown in FIG. 9. When provided as separate structures, retainingportion 440 may include a proximally extending portion 444. A distal endregion 450 of pull wire portion 438′ may be welded or otherwise suitablyattached to proximally extending portion 444.

To assemble deflection mechanism 436 with tubular member 426, a proximalend (not explicitly shown) of pull wire portion 438 may be advancedthrough a slot or aperture 446 in tubular member 426. Pull wire portion438 may pass from outside of tubular member 426 into a lumen withintubular member 426, as shown in FIG. 8B. Pull wire portion 438 mayextend proximally within the lumen to a point where it can bemanipulated by a user. Deflection mechanism 436 may be advancedproximally until a proximal edge 442 of retaining portion abuts orengages a proximal edge 448 of slot 446. Proximal edge 442 may engageproximal edge 448 such that further proximal movement or actuation ofpull wire portion 438 transfers enough force to cause deflection oftubular member 426. In some instances, retaining portion 440 may besecured to the outer surface of tubular member 426 after assembly.

FIG. 10A illustrates a side view of another illustrative tubular member526 and deflection mechanism 536. Tubular member 526 may be similar inform and function to tubular member 26 discussed above. In someinstances, tubular member 526 may include a flex body 528, flex tube532, and intermediate region 522 that may be similar in form andfunction to flex body 28, flex tube 32, and intermediate region 22discussed above, While not explicitly shown, tubular member 526 may beused in conjunction with a catheter, such as catheter 12.

The deflection mechanism 536, for facilitating deflection of the tubularmember 526 and/or catheter, may include a retaining portion 540 and apull wire portion 538. Retaining portion 540 may have tabs 542 forming a“T” shape, which is configured to be disposed within a slot 546 intubular member 526. In some instances, retaining portion 540 and pullwire portion 538 may be formed as a unitary structure, as shown in FIG.10A. In other instances, retaining portion 440 and pull wire portion 538may be formed as separate structures and subsequently secured to oneanother.

To assemble deflection mechanism 536 with tubular member 526, tabs 542may be compressed or deformed, as shown in FIG. 10B, such that retainingportion 540 may be disposed within an inner lumen of tubular member 526through slot 546. Once tabs 542 are passed through slot 546, the tabs542 may expand and assume their original orientation, as shown in FIG.10C. Pull wire portion 538 may extend along an outer surface of tubularmember 526. Deflection mechanism 536 may be advanced proximally until aproximal edge of retaining portion 540 abuts or engages a proximal edge548 of slot 546. The proximal edge of retaining portion 540 may engageproximal edge 548 such that further proximal movement or actuation ofpull wire portion 538 transfers enough force to cause deflection oftubular member 526.

FIG. 11A illustrates a side view of another illustrative tubular member626 and deflection mechanism 636. Tubular member 626 may be similar inform and function to tubular member 26 discussed above. In someinstances, tubular member 626 may include a flex body 628, flex tube632, and intermediate region 622 that may be similar in form andfunction to flex body 28, flex tube 32, and intermediate region 22discussed above, While not explicitly shown, tubular member 626 may beused in conjunction with a catheter, such as catheter 12.

The deflection mechanism 636, for facilitating deflection of the tubularmember 626 and/or catheter, may include a retaining portion 640 and apull wire portion 638. Retaining portion 640 may have an arrow shapeincluding proximal recesses 642. Retaining portion 640 may be configuredto be disposed within a slot 646 in tubular member 626. In someinstances, retaining portion 640 and pull wire portion 638 may be formedas a unitary structure, as shown in FIG. 11A. In other instances,retaining portion 640 and pull wire portion 638 may be formed asseparate structures and subsequently secured to one another, as shown inFIG. 12. When provided as separate structures, retaining portion 640 mayinclude a proximally extending portion 644. A distal end region 650 ofpull wire portion 638 may be welded or otherwise suitably attached toproximally extending portion 644.

To assemble deflection mechanism 636 with tubular member 626, distal tip652 of retaining portion 540 may be advanced distally within slot 646,as shown in FIG. 11B. Once further distal movement of retaining portion642 is prohibited by the widening structure of the arrow shape, distaltabs 652 may be compressed or deformed, such that retaining portion 640may be completely disposed within an inner lumen of tubular member 626through slot 646. Once tabs 652 are passed through slot 646, the tabs652 may expand and assume their original orientation, as shown in FIG.11C. Pull wire portion 638 may extend along an outer surface of tubularmember 626. Deflection mechanism 636 may be advanced proximally untilproximal recesses 642 of retaining portion 640 abut or engage a proximaledge 648 of slot 646. The proximal recesses 642 of retaining portion 640may engage proximal edge 648 such that further proximal movement oractuation of pull wire portion 638 transfers enough force to causedeflection of tubular member 626.

Those skilled in the art will recognize that the present invention maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent disclosure as described in the appended claims.

What is claimed is:
 1. A deflectable medical device, comprising: acatheter shaft having a distal end; an ablation electrode disposed atthe distal end; a deflection body including a longitudinally-extendingspine and wherein a first group of slots are formed in the body anddefine a first group of ribs; a flex member disposed distal to thedeflection body; an intermediate region disposed between the deflectionbody and the flex member, the intermediate region including a wallextending from the deflection body to the flex member, and an openingextending through the wall from an outer surface to an inner surface ofthe intermediate region; and a deflection mechanism coupled to theintermediate region, the deflection mechanism including a retainingportion and a pull wire portion, wherein the retaining portion comprisesa collar configured to extend around at least a portion of the outersurface of the intermediate region.
 2. The deflectable medical device ofclaim 1, wherein the collar is positioned adjacent to the opening in theintermediate region and the pull wire portion is disposed within theopening such that the pull wire portion extends proximally within alumen of the deflection body.